Carrier with exchangeable chuck

ABSTRACT

An article carrier is provided for blow molding equipment which permits relatively simple exchange of the article gripping chuck portion of the carrier. The carrier includes a carrier body, a spindle rotatably supported by the body, an article gripping chuck removeably attached to the spindle and seals between the chuck and the spindle and between the chuck and a preform retained thereby. The chuck is provided with article gripping levers preferably rotatably supported by ball and socket joints. The levers have preform grasping projections at one end and first and second ball ends at the other end. The first ball end mates with the chuck body socket and the second ball end is engaged by a lever actuating ring slidably mounted on the outside of the chuck body.

BACKGROUND OF THE INVENTION

This invention relates generally to article conveying equipment for blowmolding machinery. In particular, this invention relates to articlecarriers for blow molding machinery of the reheat and blow type.

In reheat and blow machinery, thermoplastic article preforms each havinga formed portion and a formable portion are loaded into the machine,heated to a molecular orientation temperature, and filled with anexpansion fluid to biaxially stretch the formable portion to fill a moldcavity. The resulting finished article is then ejected for collection.The formed portion is left unaltered and is suitable for receiving anarticle closure device. It is known that to maximize throughput on suchmachines handling of articles must be minimized. Thus to improve overallprocessing throughput such machines are configured to provide continuouspaths of conveyance from a preform load station to an article ejectstation, the empty conveyors being returned therefrom to the loadstation. Applicant has disclosed an article carrier suitable for usethroughout such equipment in the copending application Ser. No. 257,468assigned to the assignee of the present invention now U.S. Pat. No.4,382,760. The carrier therein disclosed is designed for use in a singlelane or conveyance path defined primarily by the construction of thereheat and blow molding sections of the machine. The result is a modularcarrier and simplified conveyor drive train. Specifically, the carrieris supported by rollers riding on rails over the horizontal portions ofthe conveyor path and is pulled therealong by incremental advances of anengaged conveyor chain.

The carrier of the aforementioned application and, in fact, thepreviously known carriers which convey the articles through reheat andblow equipment by grasping the formed portion of the preforms arelimited in application to the design of the formed portion for whichthey were originally intended. Thus, while the machine may be otherwisereadily converted to production of articles having a substantiallydifferent design including a different formed portion, the articleconveyors would require total replacement or complete rebuilding toaccomodate substantial variations in the design of the formed portion.The present invention overcomes this disadvantage while retaining theadvantages of the modular design disclosed in the aforesaid copendingapplication.

It is therefore an object of the present invention to provide an articlecarrier with a rotatable, exchangeable, article gripping chuck forreheat and blow molding equipment.

It is a further object of the present invention to provide an articlecarrier with a rotatable, exchangeable, article gripping chuck having apassage therethrough to admit the expansion fluid to the article and aseal between the chuck and the article sufficient to contain theexpansion fluid.

It is a further object of the present invention to provide an articlecarrier with a rotatable, exchangeable article gripping chuck havinggripping means operative irrespective of the rotation of the chuckwithin the carrier.

Further objects and advantages of the present invention shall becomeapparent from the following description.

SUMMARY OF THE INVENTION

In accordance with the aforesaid objects, an article carrier is providedcomprising a carrier body, a spindle rotatably mounted in the carrierbody, and an article gripping chuck removably attached to the spindle.The chuck is locked to the spindle by set screws. The spindle and chuckare provided with connecting shafts therethrough to admit an expansionfluid to an article preform being held by the chuck. Seals are providedbetween the spindle and chuck and between the chuck and article toprevent escape of the expansion fluid. The chuck is provided witharticle gripping levers operable to selectively engage and release theexterior of the formed portion of an article. The levers are operated bymovement of an annular ring slidably disposed upon the outside of thechuck and held in the article engaging position by a biasing spring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the carrier.

FIG. 2 is a section view through the carrier taken along line 2--2 ofFIG. 1.

FIG. 3 is a side view of the carrier taken in the direction of arrow 3of FIG. 2.

FIG. 4 is a bottom view taken in the direction of arrow 4 of FIG. 2 of apartial breakout showing the arrangement of article gripping levers.

FIG. 5 is a partial breakout in the direction of arrow 5 of FIG. 2showing the detail of the actuating ring retaining pin.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes of illustrating the invention, an article carrier with aremovable rotatably mounted article gripping chuck shall be described inmore detail. The particular carrier to be described is one manufacturedby Cincinnati Milacron Inc. the assignee of the present invention. Thiscarrier is designed for use in a reheat and blow type molding machinemanufactured by the aforesaid assignee.

Referring to FIG. 1, a carrier 10 is seen in top view together withlinks 106 and 108 (shown in phantom) of the carrier conveying chain.Conveyor chain link pins engage link pin blocks 30 and 32 which aremounted to carrier body 20 by mounting screws 31 and 33, respectively.The carrier body while being conveyed through the molding machine issupported by rollers 22 through 28 seen at the extreme corners ofcarrier body 20 and which ride upon rails of the machine shown inphantom in FIG. 2. Continuing with reference to FIG. 1, the spindle 40is seen in its end view within the inner diameter of spindle drivesprocket 50. Engagement of the drive sprocket 50 with spindle 40 isachieved by two opposing splines 54 and 56. Retaining ring 52 is setinto a groove in spindle 40 to hold sprocket 50 against motion towardsthe end of the spindle. During conveyance of article preforms throughthe heating portion of the machine, sprocket 50 is engaged by a chain toimpart rotation to spindle 40 to achieve even heating of the formableportion of an article preform.

Referring now to the section of FIG. 2, the article gripping chuck 60 isseen attached to the lower end of spindle 40 and held in place thereuponby set screw 80. The lower flange 42 of spindle 40 is provided with agroove 44 therein for receiving the conical ends of set screw 80 and twoadditional set screws (not shown). Spindle 40 is supported withincarrier body 20 by upper bearing 34 and lower bearing 36. Shown inphantom in this figure are the conveying chain links 106 and 108together with the expansion fluid injection nozzle 100 as it would beseated at the upper end of spindle 40, and a preform 110 includingformed portion 112. Additionally, roller support rails 102 and 104(shown in phantom) are seen supporting rollers 22 and 24 visible in thisview.

Continuing with reference to FIG. 2, it can now be appreciated thatadmission of an expansion fluid to article preform 110 is accomplishedfrom injection nozzle 100 through shaft 46 of spindle 40 and shaft 88 ofchuck 60. By providing seals at the appropriate interfaces, the escapeof expansion fluid is minimized and the finished article may besuccessfully blow molded while being retained in carrier 10.Specifically, the injection nozzle 100 carries an annular seal 101 shownin phantom at the mating surface of the top end of spindle 40 and nozzle100. Further, on the lower surface of flange 42 of spindle 40, a secondannular seal 82 is seen in section to create an expansion fluid seal atthe mating surface of chuck body 62 and spindle 40. Finally, a thirdannular seal 90 is mounted on the formed portion receiving recess ofchuck body 62 and held in place by retaining ring 91 and mounting screws92 through 96. These mounting screws and the margin of seal 90 leftexposed by retaining ring 91 are seen in the bottom view of FIG. 4. Theformed portion 112 of article preform 110 is held in position tocompress the seal by the lower ends of the article gripping levers 64through 68. The arrangement of levers 64 through 68 is seen in thebottom view of FIG. 4.

Referring again to FIG. 2, the section view shows gripping lever 64being held in the socket 89 of chuck body 62 by its ball end 61. On theopposite end of the upper T-shape of gripping lever 64, a second ballend 63 is shown in engagement with the interior groove of actuating ring70. As shown, the lower foot of gripping lever 64 is selectively held inengagement with the formed portion 112 by the relative vertical positionof actuating ring 70 effecting rotation of the lever around an axiscentered at the center of the combination of ball end 61 and socket 89.Actuating ring 70 is held in place in the article engaging position bymeans of biasing spring 76 being compressed against retaining ring 78.To release an article from the retention of gripping levers 64 through68, it is only necessary to displace annular ring 70 in the verticaldirection as indicated by the phantom lines in FIG. 2. This displacementimparts a rotation of the gripping levers 64 through 68 around theirrespective ball ends held in the associated sockets of the chuck body62.

Chuck body 62 is provided with a recess to receive the wall of formedportion 112 to achieve two ends. The chamfered edge of projecting center86 of chuck body 62 serves to aid in alignment of article preforms beinginserted into the carrier at the machine's load station. The effectivecupping around projecting center 86 created within the recess by theextension 84 of chuck body 62 serves to shield formed portion 112 fromthe heat source during conveyance of the preform through the heatingsection of the machine.

Referring now to FIG. 3, the association of actuating ring 70, biasingspring 76 and spring retaining ring 78 are more clearly revealed. Inaddition, the interior groove of actuating ring 70 for engaging theoutermost upper ball ends of gripping levers 64 through 68 is seen inphantom. Continuing with reference to FIG. 3, it is seen that chuck 60by virtue of its attachment to flange 42 of spindle 40 is held free fromany other connection to carrier assembly 10. By virtue of thisconstruction and keeping in mind that chuck body 62 is held engaged withflange 42 of spindle 40 by means of three set screws, it will beappreciated that when necessary to change the chuck assembly, it is notnecessary to remove the carrier from the machine. The entire chuckassembly may be removed from spindle 40 and replaced with another chuck,whether identical to that removed or suitable for accomodating asubstantially different design of formed portion of an article preform.Thus, by this construction that portion of the carrier which issubjected to the most wear in normal use and which is most directlydependent upon the particular size and design of articles beingmanufactured, is made readily exchangeable with a suitable substitutetherefore.

Referring to FIG. 5, the portion of actuating ring 70 in the immediatevicinity of the retaining slot 74 is shown in a partial detail breakout.To install gripping levers 64 through 68, the actuating ring is rotatedto align slot 74 with a gripping lever accepting slot in chuck body 62such as slot 65 of FIG. 3. The lever is then inserted, and the actuatingring 70 is rotated to move slot 74 out of alignment with the grippinglever. When all gripping levers have been thus installed, the actuatingring 70 is rotated to align slot 74 with the retaining pin hole 73 inchuck body 62 shown in FIGS. 2 and 4. The retaining pin is then insertedto restrain ring 70 against rotation relative to chuck body 62. Therelative position of pin 72 and the article gripping levers is shown inFIGS. 2 and 4.

It will be appreciated by those skilled in the art that variousarrangements of a number of article gripping levers and chuck bodydesigns may be employed. It is not the intention of applicant to limitthe scope of the present invention to any particular spatial arrangementof article gripping levers or any particular design of the chuck body atthe article receiving end. Nor are the details of the rotation drivesprocket to be contrued as limitations, a suitable friction drive wheelor drive gear being acceptable substitutes. Further, while the inventionhas been illustrated in some detail, according to the preferredembodiment shown in the accompanying drawings and while the preferredillustrated embodiment has been described in some detail, there is nointention to thus limit the invention to such detail. On the contrary,it is intended to cover all modifications, alterations and equivalentsfalling within the spirit and scope of the appended claims.

What is claimed is:
 1. An article carrier for use in a reheat and blowmolding machine for forming a finished article from a thermoplasticarticle preform having a formable portion and a formed portion, theformable portion being expanded in a mold cavity of the molding machineby injection of an expansion fluid into the preform after adjusting thetemperature thereof to the molecular orientation temperature, thecarrier comprising:(a) a carrier body; (b) a spindle rotatably supportedwithin the carrier body and having a passage therethrough for admissionof the expansion fluid; (c) an article gripping chuck removeablyattached to the spindle for releasably retaining article preforms andhaving a passage therethrough for admission of the expansion fluid fromthe spindle, the chuck further including:(1) at least two articlegripping levers rotatably mounted on the chuck for releasably graspingarticle preforms by the exterior of the formed portion; (2) a leveractuator ring slidably disposed upon the outside of the chuck forimparting rotation to the levers; and (3) an actuator ring biasing meansconnected between the ring and the chuck for holding the actuator at oneextreme of its travel to maintain the levers in an article retainingposition; (d) first sealing means for forming a seal between the spindleand the chuck sufficient to withstand the forces of expansion; and (e)second sealing means for forming a seal between the chuck and thearticle sufficient to contain the expansion fluid admitted to thearticle preform.
 2. The apparatus of claim 1 wherein the chuck is formedto provide a shield around the exterior of the formed portion of anarticle preform retained by the chuck.
 3. The apparatus of claim 2wherein the second sealing means further comprises an annular sealingring disposed within the recess circumscribed by the chuck shield andsurrounding the passage therethrough.
 4. The apparatus of claim 1further comprising:(a) rotation drive means attached to one end of thespindle; and (b) a chuck mounting flange at the other end of thespindle.
 5. The apparatus of claim 4 wherein the first sealing meansfurther comprises an annular sealing ring disposed upon the lower faceof the flange and surrounding the passage therethrough.